This is an example based on mbed-os cellular APIs that demonstrates a TCP or UDP echo transaction with a public echo server. Included TPB23 NB-IoT module which is can use LGU+ in Korea.

This example is showing how to use the NB-IoT(SECOM TPB23 module) of LGU plus network in Korea. The NB-IoT module' seller provided a document on how to start based on Mbed OS 5.11. (Created by CodeZoo) This guide has been supported to the latest os version which included 5.12 ~ 5.15.

  • if you need specific version of Mbed OS, please revision of TPB23_Driver and check it out.
  • Pelion ready example code is here!

Requirement

462 320 320

320

Tested with

1. Import the application into your desktop

mbed import http://os.mbed.com/users/Daniel_Lee/code/mbed-os-example-cellular-TPB23/

cd mbed-os-example-cellular-TPB23

2. Compile and program

mbed compile -t <toolchain> -m <TARGET_BOARD>

(supported toolchains : GCC_ARM / ARM / IAR)

3. Download binary to a target board

4. Result

mbed-os-example-cellular


Built: Aug  7 2019, 06:10:47


[MAIN], plmn: NULL
Establishing connection
[00000001ms][INFO][CELL]: New CellularContext  (20000a08)
[00000002ms][INFO][CELL]: CellularContext plmn NULL
[00000003ms][INFO][CELL]: CellularContext connect
[00000036ms][INFO][CELL]: RSSI -69 dBm
[00000036ms][INFO][CELL]: Start connecting (timeout 1 s)
[00000087ms][INFO][CELL]: RSSI -69 dBm
[00000116ms][INFO][CELL]: Modem ready
[00000146ms][INFO][CELL]: RSSI -69 dBm
[00000146ms][INFO][CELL]: Setup SIM (timeout 1 s)
[00001233ms][INFO][CELL]: Looked up APN internet
[00001362ms][ERR ][CELL]: AT error code 50
[00001362ms][WARN][CELL]: Packet domain event reporting set failed!
[00001393ms][INFO][CELL]: RSSI -65 dBm
[00001393ms][INFO][CELL]: Network registration (timeout 180 s)
[00001443ms][INFO][CELL]: Registering network => Attaching network
[00001473ms][INFO][CELL]: RSSI -65 dBm
[00001473ms][INFO][CELL]: Attaching network (timeout 60 s)
[00001601ms][INFO][CELL]: Found PDP context 1
[00001649ms][INFO][CELL]: Activate PDP context 1


Connection Established.
[00001671ms][INFO][CELL]: Socket 0 open
[00001707ms][INFO][CELL]: Socket 1 open
[00001748ms][INFO][CELL]: Socket create id: 1
[00001883ms][INFO][CELL]: Socket 1 sent 43 bytes to 8.8.8.8 port 53
[00004311ms][INFO][CELL]: Socket 1 recv 59 bytes from 8.8.8.8 port 53
[00004331ms][INFO][CELL]: Close socket: 1 error: 0
[00004331ms][INFO][CELL]: Socket 1 closed
[00004373ms][INFO][CELL]: Socket create id: 1
TCP: connected with echo.mbedcloudtesting.com server
[00004448ms][INFO][CELL]: Socket 0 sent 4 bytes to 52.215.34.155 port 7
TCP: Sent 4 Bytes to echo.mbedcloudtesting.com
[00007560ms][INFO][CELL]: Socket 0 recv 4 bytes
[00007580ms][INFO][CELL]: Close socket: 1 error: 0
[00007580ms][INFO][CELL]: Socket 0 closed
Received from echo server 4 Bytes
[00007581ms][INFO][CELL]: CellularContext disconnect()
[00007630ms][INFO][CELL]: cb: CellularContext disconnected


Success. Exiting
Revision:
11:23ea0907186e
Parent:
6:5678c0b6f74e
Child:
16:bf6ed28b4d08
--- a/README.md	Wed Jun 06 07:45:26 2018 +0100
+++ b/README.md	Mon Jun 18 09:00:19 2018 +0100
@@ -61,13 +61,10 @@
 
 ### Turning modem AT echo trace on
 
-If you like details and wish to know about all the AT interactions between the modem and your driver, turn on the modem AT echo trace. Set the `modem_trace` field value to be true.
+If you like details and wish to know about all the AT interactions between the modem and your driver, turn on the modem AT echo trace.
 
 ```json
-        "modem_trace": {
-            "help": "Turns AT command trace on/off from the cellular modem, defaults to off",
-            "value": true
-        },
+        "cellular.debug-at": true
 ```
 
 ### Turning on the tracing and trace level
@@ -76,8 +73,8 @@
 
 ```"target_overrides": {
         "*": {
-            "target.features_add": ["LWIP", "COMMON_PAL"],
-            "mbed-trace.enable": false,
+            "target.features_add": ["LWIP"],
+            "mbed-trace.enable": true,
 ```
 
 After you have defined `mbed-trace.enable: true`, you can set trace levels by changing value in `trace-level`
@@ -126,4 +123,12 @@
 
 ## Troubleshooting
 
-If you have problems, you can review the [documentation](https://os.mbed.com/docs/latest/tutorials/debugging.html) for suggestions on what could be wrong and how to fix it.
+* Make sure the fields `sim-pin-code`, `apn`, `username` and `password` from the `mbed_app.json` file are filled in correctly. The correct values should appear in the user manual of the board if using eSIM or in the details of the SIM card if using normal SIM.
+* Enable trace flag to have access to debug information `"mbed-trace.enable": true`.
+* Try both `TCP` and `UDP` socket types.
+* Try both `"lwip.ppp-enabled": true` and `"lwip.ppp-enabled": false`.
+* The modem may support only a fixed baud-rate, such as `"platform.default-serial-baud-rate": 9600`.
+* The modem and network may only support IPv6 in which case `"lwip.ipv6-enabled": true` shall be defined.
+* The SIM and modem must have compatible cellular technology (3G, 4G, NB-IoT, ...) supported and cellular network available.
+
+If you have problems to get started with debugging, you can review the [documentation](https://os.mbed.com/docs/latest/tutorials/debugging.html) for suggestions on what could be wrong and how to fix it.